On Thu, Mar 03, 2005 at 02:28:43PM -0800, David Schwartz wrote: [ snip ]
Every piece of BGP documentation I have ever seen says that this attribute documents the ASes that the route has actually passed through.
Do I need to get permission from Sprint before I include 1239:100 as a community-string attribute on my own advertisement, too?
You certainly need their permission before you can advertise routes that falsely came to have passed through their network!
What kind of specific _technical_ issue do I create by prepending another ASN on AS_PATHs I advertise, without such "owner"'s permission?
that you do need permission to attach someone else's community string to your routes and that it would be considered at least terribly bad manners to use undocumented community strings from other people's ASes. (Documentation, of course, equates to permission.)
Please, that's ridiculous. [ snip ]
I'm curious where you would draw the line then. And I'm curious what you think is the point of registering AS numbers at all, if it's okay to use other people's without their permission.
If you are concerned about accuracy of registration records, I would advise that you ensure that your origin AS (aka the last ASN showing up before 'i' on Cisco or 'I' on Juniper in show output) in the AS_PATH is accurate. I don't see any technical pitfalls to include someone else's ASN in the transit path to avoid that particular ASNs from seeing it, other than the fact that is generally a frowned-upon or tasteless act to do. -J